Objectives: Traditional breast cancer treatments have challenges including inefficiency, multidrug resistance, severe side effects, and targeting non-specifically. The development of alternative treatment strategies has attracted a great deal of interest. Using the amniotic membrane has become a promising and convenient new approach for cancer therapy. This study aimed to evaluate the anti-cancer ability of conditioned medium extracted from the human amniotic membrane (hAM-CM) on breast cancer cells. Methods: Conditioned medium was collected after 48 h incubation of hAM in epithelial up manner. MTT, cell cycle, apoptosis, colony formation, and sphere assays were used to determine the impact of hAM-CM on breast cancer cell lines. The effects of hAM-CM on the migration and invasion of breast cancer cells were determined using scratch wound healing and transwell assays, respectively. Results: Based on the results, cell viability was significantly decreased by hAM-CM in a dose-dependent manner. The hAM-CM remarkably induced apoptosis and necrosis of cancer cells. Moreover, cell migration and invasion potential of cancer cells decreased after the hAM-CM treatment. Further, both the number of colonies and their morphologies were affected by the treatment. In the treated group, a significant decrease in the number of colonies along with an obvious change in their morphologies from holoclone shape to a dominant paracolone structure was observed. Conclusion: Our results indicate that the conditioned medium derived from the human amniotic membrane able to inhibit proliferation and metastasis of tumor cells and can be considered a natural and valuable candidate for breast cancer therapy. [ABSTRACT FROM AUTHOR]